The standard Sound Bombs are driven by a compressor and require space and wiring. The Sound Bomb Mini is a direct swap for the OEM horn and whilst not the klaxon of the full size versions is way better, cheap and a somple install.
I just purchased the Nautilus compressor Horn for my 1100 sport and will install it over the winter time with a relay. I had one of those at my previous BMW R1200GS and was very satisfied with the sound.... I will post a photo once it is installed.